Toward Ecosophy

Ashtanga yoga should be fine in combination with basic magical training of the kind taught in Learning Ritual Magic; if you go on to the more advanced forms of pranayama, that might become problematic, but if you're focusing on the physical-exercise end of yoga you should be fine. As for the rituals, you may do any of those things, depending on which you prefer -- as long as the names and words of power aren't changed, the rest can be put in any language you like.